Process of desiccating plants

ABSTRACT

Compounds of the formulae   WHERE R1 and R2 are hydrogen, alkyl, chloroalkyl, phenyl and alkyl phenyl, X is halogen, Y is nitro, m is an integer from 1 to 2 and n is an integer of 1 to 3 are useful as herbicides and desiccants and to a lesser extent as defoliants. For the best desiccant properties there should be a halogen in the ortho position of the chloronitrophenyl group.

United States Patent Delta W. Gier Laurinburg, N.C.;

Daniel M. Wasleski, Kansas City, Mo. 675,350

Oct. 16, 1967 Jan. 4, 1972 Chemagro Corporation New York, N.Y.

[72] Inventors [21] Appl. No. [22] Filed [45] Patented [73] Assignee [54] PROCESS OF DESICCATING PLANTS OTHER REFERENCES Derwent Belgian Report No.52 B. P. A3, May 1959 Primary Examiner.lames 0. Thomas, Jr. Att0rneyCushman, Darby & Cushman ABSTRACT: Compounds of the formula Xn Ym where R, and R are hydrogen, alkyl, chloroalkyl, phenyl and alkyl phenyl, X is halogen, Y is nitro, m is an integer from 1 to 2 and n is an integer of l to 3 are useful as herbicides and desiccants and to a lesser extent as defoliants. For the best desiccant properties there should be a halogen in the ortho position of the chloronitrophenyl group.

PROCESS OF DESICCATING PLANTS The present invention relates to novel herbicides and desiccants.

it is an object of the invention to develop improved compositions and methods for killing undesired plants. 5

Another object is to develop improved compositions and methods for desiccating plants.

Another object is to develop improved compositions and methods for defoliating plants.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

It has now been found that these objects can be attained by employing as herbicides, desiccants or defoliants compounds having one of the following formulas RrOOCCHCHCOORz Xn Ym Xn Ym or RiOOCICHCH2COORg Xn Yni where R and R are hydrogen, alkyl, chloroalkyl, phenyl and alkylphenyl, X is halogen, preferably chlorine or bromine, Y is nitro, m is an integer of 1 to 2 and n is an integer of 1 to 3.

The compounds of formula (1) of the present invention are prepared by reacting 1 mole of the appropriate halonitrophenol with 0.5 mole of the appropriate 0.8- dihalosuccinic acid or ester thereof. The compounds of formula (2) are prepared by reacting 1 mole of the appropriate halonitrophenol with l mole of maleic acid or ester thereof. In preparing the compounds of formulas (l) and (2) the reaction is carried out in the presence of a base, e.g. sodium hydroxide, potassium hydroxide or the like in the presence of an inert solvent, e.g. dirnethoxyethane (ethylene glycol dimethyl ether) or acetone.

As the halonitrophenol there can be employed 2,4,5- trichloro- 6- nitrophenol, 2,4- dichloro- 6- nitrophenol, 2- chloro- 4 nitrophenol, 2- nitro- 4- chlorophenol, 2,4,6- trichloro- 5- nitrophenol, 2,3,4- trichloro- 5- nitrophenol, 2,6- dichloro- 4- nitrophenol, 2- nitro- 3,4- dichlorophenol, 3- chloro- 460 nitrophenol, 2,4,6- tribromo- 6- nitrophenol, 2,4- dibromo- 6- nitrophenol, 2,4,5- trifluoro- 6- nitrophenol, 2- chloro- 4,6-

- diphenyl succinate, a,B-dibromo di-p-tolyl succinate,a ,B-

dibromo di- 2- chloroethyl succinate, a ,B- dibromo di- 3- bromopropyl succinate, maleic acid, dimethyl maleate, diethyl maleate, dipropyl maleate, dibutyl maleate, diamyl maleate, dihexyl maleate, dioctyl, maleate, diphenyl maleate, di ptolyl,

maleate, di p-butylphenyl maleate, di-2- chloroethyl maleate, di- 3- chloropropyl maleate.

Examples of compounds useful in the present invention are a,B- bis (2,4- dichloro-6-nitrophenyl) tartaric acid diether (prepared from 2,4- dichloro-6-nitrophenol and a ,B- dibromosuccinic acid), a,B-bis (2,4,5-trichloro- 6-nitrophenyl tartaric acid diether, a,B- bis (2,4,5- trichloro-6-nitrophenyl) dimethyl tartrate diether, a,B- bis (2,4,5-trichloro-6- nitrophenyl) diethyl tartrate diether, a,B- bis (2,4,5- trichloro- 6-nitrophenyl) dibutyl tartrate diether, a ,B- bis (2,4,5- trichloro-6-nitrophenyl) dihexyl tartrate diether, a ,B- bis (2,4,5-trichloro-o-nitrophenyl) dicyclohexyl tartrate diether, a,B- bis (2,4,5- trichloro- 6- nitrophenyl) dioctyl tartrate diether, a,B- bis (2,4,5-trichloro-6-nitrophenyl) diphenyl tartrate diether, a,B- bis 2,4,5- trichloro- 6- nitrophenyl) diptolyl tartrate diether, a,B- bis (2,4,5-trichloro-o-nitrophenyl) di pbutylphenyl tartrate diether, a,B- bis (2,4,5-trichloro-6-nitrophenyl) di 2-chloroethyl tartrate diether, a ,B- bis (2,4,5- tribromo- 6-nitrophenyl) tartrate acid diether,a ,B- bis (2,4,5- trifluoro-6-nitrophenyl) diethyl tartrate diether,a ,B- bis (2,4 dichloro-6- nitrophenyl) diethyl tartrate diether,a ,B- bis (2,4- dichloro-6-nitrophenyl) dimethyl tartrate diether, a ,B-bis (2,4- dichloro-6-nitrophenyl) dihexyl tartrate diether,a ,B- bis (2- chloro-4-nitrophenyl) tartaric acid diether, a ,B-bis (4- chloro- 2- nitrophenyl) tartaric acid diether, a ,B-bis (2,6- dichloro-4-nitrophenyl) tartaric acid diether, a ,B- bis (4- chloro- 2,6- dinitrophenyl) tartaric acid diether, 2,4,5- trichloro-6-nitrophenyl diethyl malate ether (from 2,4,5- trichloro-6-nitrophenol and diethyl maleate), 2,4,5- trichloro- -nitrophenyl malic acid ether 2,4- dichloro-o-nitrophenyl malic acid ether, 2,4,5- trichlorl-6-nitrophenyl dimethyl malate ether, 2,4- dichloro- 6- nitrophenyl di sec butyl malate ether, 2,4,5-t1ichloro- 6-nitrophenyl dioctyl malate ether, 2,4,5- tribromo-6-nitrophenyl diisopropyl malate ether, 2- chloro- 4- nitrophenyl diphenyl malate ether.

The compounds of the present invention can be used alone or they can be applied together with inert solids to form dusts, or can be suspended in a suitable liquid diluent, preferably comprising water.

There can also be added surface active agents or wetting agents and/or inert solids in the liquid formulations. In such case, the active ingredient can be from 0.01 to percent by weight of the entire composition.

In place of water there can be employed organic solvents as carriers, e.g., hydrocarbons such as benzene, toluene, xylene, kerosene, diesel oil, fuel oil, and petroleum naphtha, ketones such as acetone, methyl ethyl ketone and cyclohexamone, chlorinated hydrocarbons such as carbon tetrachloride, chloroform, trichloroethylenc and perchloroethylene, esters such as ethyl acetate, amyl acetate and butyl acetate, ethers, e.g., ethylene glycol monomethyl ether and diethylene glycol monomethyl ether, alcohols, e.g., ethanol, methanol, isopropanol, amyl alcohol, ethylene glycol, propylene glycol, butyl carbitol acetate and glycerine. Mixtures of water and organic solvents, either as solutions or emulsions, can be employed.

The novel compounds can also be applied as aerosols, e.g., by dispersing them in air by means of a compressed gas such as dichlorodifluoromethane or trichlorofluoromethane and other Freons, for example.

The compounds of the present invention can also be applied with adjuvants or carriers such as talc, pyrophyllite, synthetic fine silica, attapulgus clay (attaclay), kieselguhr, chalk, diatomaceous earth, lime, calcium carbonate, bentonite, fullers earth, cottonseed hulls, wheat flour, soybean flour, pumice, Tripoli, wood flour, walnut shell flour, redwood flour and lignin.

As stated, it is frequently desirable to incorporate a surfaceactive agent in the compositions of the present invention. Such surface active or wetting agents are advantageously employed in both the solid 'and liquid compositions. The surfaceactive agent can be anionic, cationic or nonionic in character.

Typical classes of surfaceactive agents include alkyl sulfonate salts, allrylaryl sulfonate salts, alkyl sulfate salts, alkylamide sulfonate salts, alkylaryl polyether alcohols, fatty acid esters of polyhydric alcohols and the alkylene oxide addition products of such esters, and addition products of long chain mercaptans and alkylene oxides. Typical examples of such surface active agents include the sodium alkylbenzene sulfonates having 10 to 18 carbon atoms in the alkyl group, alkylphenol ethylene oxide condensation products, e.g., pisooctylphenol condensed with 10 ethylene oxide units, soaps, e.g., sodium stearate and potassium oleate, sodium salt of propylnaphthalene sulfonic acid (di- 2- ethylhexyl), ester of sodium sulfosuccinic acid, sodium lauryl sulfate, sodium salt of the sulfonated monoglyceride of cocoanut fatty acids, sorbitan sesquioleate, lauryl trimethyl ammonium chloride, octadecyl trimethyl ammonium chloride, polyethylene glycol lauryl ether, polyethylene esters of fatty acids and rosin acids, e.g., Ethofat 7 and 13, sodium N- methyl- N- oleyltaurate, Turkey Red Oil, sodium dibutylnaphthalene sulfonate, sodium lignin sulfonate (Marasperse N), polyethylene glycol stearate, sodium dodecylbenzene sulfonate, tertiary dodecyl polyethylene glycol thioether (nonionic 218), long chain ethylene oxidepropylene oxide condensation products, e.g., Pluronic 6l (molecular weight 1,000), sorbitan sequioleate,

polyethylene glycol ester of tall oil acids, sodium octyl phenoxyethoxyethyl sulfate, tris (polyoxyethylene) sorbitan monostearate (Tween 60), and sodium dihexyl sulfosuccinate.

The solid and liquid formulations can be prepared by any of the conventional procedures. Thus, the active ingredient, in finely divided form if a solid, may be tumbled together with finely divided solid carrier. Alternatively, the active ingredient in liquid form, including solutions, dispersions, emulsions and suspensions thereof, may be admixed with the solid carrier in finely divided form.

The compounds of the present invention can be applied to soil, growing plants, e.g., trees, cotton plants, wheat and other grain plants, vegetable plants, seeds and fabrics.

Unless otherwise indicated, all parts and percentages are by weight.

. .E MP

In preparing the compounds set forth in table 1, there was carried out either reaction A or B.

. .REACTIONA A solution of 0.1 mole of the appropriate phenol and 20 ml. of 10 normal aqueous sodium hydroxide in 200 ml. of dimethoxyethane was placed in a flask equipped with a mechanical stirrer and reflux condenser. 0.05 mole of a3- dibromosuccinic acid was added and the mixture heated to reflux for 35-40 hours. The resulting solution was poured over chipped ice, acidified with hydrochloric acid, collected in a Buchner funnel, washed with water and dried under vacuum. The products thus produced were within Formula 1) supra.

REACTION B A solution of 0.1 mole of 2,4,5- trichloro- 6- nitrophenol, 0.1 mole of diethyl maleate, and drops hydrochloric acid in 200 ml. of dimethoxyethane was placed in a flask equipped with a mechanical stirrer and a reflux condenser. The mixture was heated to reflux for 8 to 10 hours. The resulting solution was cooled, poured into 200 ml. of chloroform and subsequently washed with two 500 ml. portions of water. After drying over calcium sulfate, the chloroform was removed in a rotary evaporator under vacuum to give the desired product in fairly high purity. The product produced was within formula (2) supra. It was 2,4,5-trichloro-6- nitrophenyl diethyl malate ether.

7 TABLE 1 Compound 7 does not have a nitro group and is included to show the increased desiccant effect when a nitro group is present.

The compounds of the present invention have been applied in many instances as wettable powders consisting of 50 percent of the active ingredient, 46 percent ultrafine silica (Hi- Sil), 2 percent sodium lignin sulfonate and 2 percent Pluronic L-6l (polyetylene oxidepolypropylene oxide adduct molecular weight about 1000). This wettable powder is hereinafter designated as formulation A.

EXAMPLE 2 The compounds of the present invention were tested as defoliants and desiccants for cotton when applied as formulation A dispersed in water. The results are set forth in table 2 with the rates expressed in lbs/acre.

It will be observed that the presence of halogen, e.g. chlorine or bromine in the ortho or 2 position rendered the compound much more effective as a desiccant, compare compound 3 with compound 4 or compound 6. It will also be observed that the presence of a nitro group enhances desiccant activity, compare compound 2 with compound 7. The desiccants also exhibited good regrowth control, low mammalian toxicity and noncorrosive properties.

EXAMPLE 3 The compounds of the present invention also slowed preemergent and postemergent herbicidal activity when using formulation A at the indicated dosages of active ingredient in lbs/acre. The preemergent herbicide results are set forth in table 3 and the postemergent herbicide results are set forth in table 4. In table 3 a 0-10 scale is employed with 0 indicating percent germination and 10 indicating no germination. In table 4 a 10 scale is employed with 0 indicating no kill and 10 indicating 100 percent kill TABLE 3 Sugar Compound lbs/acre Oats beets Radish Flax Wheat 8 20 6 IO 10 I0 5 10 4 9 9 8 3 1 I 30 8 IO l0 l0 8 i 10 7 10 9 8 4 Yield, M.P.,

Compound X Y R percent C. 20 MD Formula 2,4,5-triehloro. 6nitro H 65 1 2,4-dichloro. 6-nitro H 55 1 4-chl0ro 2-nitro II 62 l 2,6-dichloro -nitro. H 73 l t-chloro 2,6-dinitro H 71 88 l 2,4-dichloro Hydrogen H 88 1.5195 1 8 2,4,5-trichloro dnitrm 71 1.4990 2 1 Ethyl. Liquid.

What is claimed is: l. A process of desiccating plants comprising applying an effective amount of a compound having the formula Rl-OOCCHCHCOORZ RiOOCCHCHzCOO-Ra 0 Xn Ym X11 +Ym or Xn Yin where R and R are selected from the group consisting of hydrogen, alkyl, chloroalkyl, phenyl and alkylphenyl, X is selected from the group consisting of chlorine, bromine and fluorine, Y is nitro, m is an integer of l to 2 and n is an integer of l to 3.

2. A process according to claim 1 wherein the compound has formula l) and X is chlorine or bromine.

3. A process according to claim 2 wherein the ortho position on the halonitrophenyl groups is substituted with chlorine or bromine.

4. A process according to claim 3 wherein R and R are lower alkyl.

5. A process according to claim 3 wherein R and R, are hydrogen.

6. A process according to claim 3 wherein n is 2 or 3 and m is l.

7. A process according to claim 1 wherein the compound has formula (2) and X is chlorine or bromine.

8. A process according to claim 7 wherein the ortho position on the chloronitrophenyl group is substituted with chlorine or bromine.

9. A process according to claim 8 wherein R, and R are lower alkyl.

10; A process according to claim 9 wherein n is 2 or 3 and m is l.

11. A process according to claim 8 wherein R and R are hydrogen.

12. A process according to claim 11 wherein n is 2 or 3 and m is l.

13. A process according to claim 11 wherein R and R are ethyl. 

2. A process according to claim 1 wherein the compound has formula (1) and X is chlorine or bromine.
 3. A process according to claim 2 wherein the ortho position on the halonitrophenyl groups is substituted with chlorine or bromine.
 4. A process according to claim 3 wherein R1 and R2 are lower alkyl.
 5. A process according to claim 3 wherein R1 and R2 are hydrogen.
 6. A process according to claim 3 wherein n is 2 or 3 and m is
 7. A process according to claim 1 wherein the compound has formula (2) and X is chlorine or bromine.
 8. A process according to claim 7 wherein the ortho position on the chloronitrophenyl group is substituted with chlorine or bromine.
 9. A process according to claim 8 wherein R1 and R2 are lower alkyl.
 10. A process according to claim 9 wherein n is 2 or 3 and m is
 11. A process according to claim 8 wherein R1 and R2 are hydrogen.
 12. A process according to claim 11 wherein n is 2 or 3 and m is
 13. A process according to claim 11 wherein R1 and R2 are ethyl. 